CN1167891A

CN1167891A - Steam trap

Info

Publication number: CN1167891A
Application number: CN 96107676
Authority: CN
Inventors: 尚德敏
Original assignee: Individual
Current assignee: Individual
Priority date: 1996-06-12
Filing date: 1996-06-12
Publication date: 1997-12-17

Abstract

A steam trap without movable parts is composed of casing. filtering net and perforated plate. Said perforted plate has drainage holes in different diameters for choosing them. Each drainage holes is connected to a straight pipe with open lower end. Said straight pipe has a internal diameter equal to the diameter of drainage hole and a length 15 time longer than its internal diameter. Its advantages are simple structure, high reliability, and wide adaptability for different and changeable pressures and loads.

Description

Steam trap

The present invention relates to a kind of steam trap connection that is used for gas utilization unit discharged steam water of condensation, especially do not have the steam trap of movable part.

At present, generally there is contradiction in steam trap commonly used between usability and functional reliability, wherein to discharge saturated water of condensation performance good for float-ball type, float bowl-type, pulsed and thermodynamic trap, but because of it has movable part, as lever, spool or valve disc,, cause mechanical failure easily owing to reasons such as wearing and tearing, foreign matter obstructions, in addition, float-ball type and bucket trap discharged air performance are bad; Expansion steam trap utilizes the small temperature difference between steam and the water of condensation to move, and it can not discharge saturated water of condensation; The orifice-plate type STEAM TRAP is simple in structure, no-movable part, and reliable operation, but usability is undesirable, and it can not adapt to the variation with steam pressure, and especially it can not adapt to gas utilization unit is warmed up to temperature-constant operation process steam load from startup variation.

The purpose of this invention is to provide a kind of steam trap, it is simple in structure, does not have movable part, reliable operation, and it can adapt to gas utilization unit moves with under the steam pressure multiple, also can adapt to the variation with the vapour load.

For achieving the above object, the solution that the present invention adopts is: on the basis of existing orifice plate STEAM TRAP, make the single hole orifice plate into the porous orifice plate, such as 3 or 4 weep holes can be arranged, along hydrophobic flow direction, respectively pick out a bit of normal straight tube that is known as drain pipe on each weep hole, the drain pipe internal diameter is identical with connecing weep hole diameter.Before use, determine required hydrophobic area according to loading with steam pressure with vapour of gas utilization unit, this hydrophobic area can be reached by the part weep hole area sum of selecting for use, and no weep hole is blocked up, so, the present invention applicable to multiple with steam pressure with multiplely load with vapour.Start between temperature raising period at gas utilization unit, the condensing capacity of generation is bigger, and the water temperature of condensing is lower than the saturated-steam temperature in the gas utilization unit, when this undersaturated water of condensation enters drain pipe by weep hole, do not vaporize or seldom vaporization, flow resistance is little, and the hydrophobic flow that passes through is bigger; During the gas utilization unit temperature-constant operation, condensing capacity is less, produce saturated water of condensation, when it enters drain pipe by weep hole, because of step-down is vaporized, produce than big a lot of two-phase flow resistance of single phase flow dynamic resistance and acceleration flow resistance, make the saturated condensing capacity that passes through also less, so the present invention can adapt to gas utilization unit is warmed up to temperature-constant operation process steam load from startup variation.

Advantage of the present invention is: (1) is simple in structure, does not have movable part, reliable operation; (2) can adapt to the multiple steam pressure and multiple with the vapour load of using, especially it can adapt to gas utilization unit is warmed up to temperature-constant operation process steam load from startup variation; (3) can the saturated water and air that condenses of continuous blow-down.

Below in conjunction with accompanying drawing specific embodiments of the invention are described in further detail.

Fig. 1 is the embodiment's of a steam trap of the present invention cross-section structure.

Fig. 2 is the cross-section structure of the filter screen in the embodiment of the invention.

Fig. 3 is the part section structure of the orifice plate among the present invention.

Fig. 4 is the cross-section structure of the drain pipe among the present invention.

In the represented embodiments of the invention of Fig. 1, perpendicular to orifice plate 3 by the represented hydrophobic flow direction of arrow, the inner space of the housing 1 of steam trap is separated into into the water space and goes out water space two-part, and filter screen 2 places into water space, is used for filtering out hydrophobic impurity.3 weep holes 4 are arranged on the orifice plate 3 of present embodiment, before each weep hole 4 inlets one section tapped hole are arranged, and be furnished with plug 5, if this hole need not, available institute wire distribution stifled 5 is shut.Along hydrophobic flow direction, from each weep hole 4, respectively pick out one section drain pipe 6, the internal diameter of drain pipe 6 is identical with the diameter d of connecing weep hole 4, the other end opening the going out in the water space at STEAM TRAP housing 1 of drain pipe 6.The diameter d of 3 weep holes 4 has nothing in common with each other usually, the selection principle of its value size is the various combinations that make 3 hydrophobic areas of 3 weep holes 4, comprise appointing and get 1,2,3 weep holes 4, formed hydrophobic area series of values is the hydrophobic areal extent of topped a certain practicality evenly.Such as the diameter d of selecting 3 weep holes 4 be respectively 1.6,2.3,3.2mm, the hydrophobic surface integration of 3 weep holes 4 is not approximately 2,4,8mm ², by the formed hydrophobic area series of values of their various combinations be 2,4,6,8,10,12,14mm ², therefore this selection just can be at 2～14mm ²Practical hydrophobic area is provided in the scope.

At given saturated condensing water flow m (kg/h) and hydrophobic pressure differential deltap p (10 ⁵Pa) under the condition, do a large amount of hydrophobic experiments, through to the arrangement of experimental result, provided the following hydrophobic area A (mm of practicality of the present invention that is applicable to ²) formula:

A = \frac{0.785}{25.9 - 0.01 B} \times \frac{B}{\sqrt{ΔP}}

In the formula: this formula of B=m (2.5+0.05 Δ P) is applicable to Δ P≤10 * 10 ⁵Pa, m＜400kg/h.The selection of each drain pipe 4 length is to consider under identical hydrophobic pressure reduction, makes the difference maximum of the saturated condensing water flow that passes through and unsaturated condensing water flow.Experimental result shows, as the length L=30～100mm of drain pipe 4, hydrophobic pressure differential deltap p=(1～10) * 10 ⁵During Pa, unsaturated condensing water flow is 3～5 with the ratio of saturated condensing water flow.The optimal selection of drain pipe 4 length L is relevant with drain pipe 4 inner diameter d, and according to experimental result, the optimum length of drain pipe 4 is L=15d.

Describe hydrophobic flow process among the present invention below in detail: if given hydrophobic pressure differential deltap P=5 * 10 ⁵Pa, saturated condensing water flow m=200kg/h, obtaining practical hydrophobic area by the formula of the practical hydrophobic area A of aforementioned calculating is 9.46mm ²In 3 weep holes 4 of present embodiment, diameter be 1.6 and the hydrophobic area sum of two weep holes of 3.2mm be 10mm ², suitable with the hydrophobic area of required practicality, be weep hole usefulness plug 5 stifled last the getting final product of 2.3mm with another diameter.Gas utilization unit starts in the temperature-rise period, and the low temperature ponding in the unsaturated water of condensation of generation and gas utilization unit, the discharge pipe line enters steam trap together, and flow is bigger.These unsaturated water enter housing 1 of the present invention along the direction of arrow, through filter screen 2, by the weep hole 4 of two openings, enter drain pipe 6 again.Unsaturated water is when flowing through weep hole 4 and drain pipe 6, though because the local flow resistance is arranged and along the journey flow resistance and pressure reduces, do not vaporize or have only seldom vaporization, flow resistance is less, the flow that passes through is bigger, can bleed off low temperature ponding and unsaturated water of condensation quickly.After gas utilization unit reaches normal working temperature, condensing capacity reduces, the water of condensation that is produced is a saturation water, when flowing through weep hole 4 and drain pipe 6, saturated water of condensation produces vaporization, therefore produce the two-phase flow resistance and quicken flow resistance, this flow resistance than single-phase water is a lot of greatly, thereby make saturated water of condensation less by the flow of drain pipe 6, because hydrophobic area is selected by saturated condensing capacity, so the flow that saturated water of condensation is passed through just in time equals the saturated condensing capacity that gas utilization unit produces.Usually selected hydrophobic area can be a bit larger tham by the practical hydrophobic area of aforementioned formula calculating gained, but, both made selected hydrophobic area slightly little, the STEAM TRAP water lines ponding that comes is detained, because the cooling of pipeline heat radiation ponding, during by weep hole and drain pipe, evaporating capacity reduces, flow resistance reduces, and flow increases.Therefore if STEAM TRAP comes water lines that certain-length is arranged, and heat radiation better, and the present invention also has to a certain degree automatic compensation function to selecting hydrophobic area situation less than normal for use.

As the filter screen in the represented embodiment of the invention of Fig. 2, it is made up of bushing 2a and flange 2b.Bushing 2a material is a corrosion resistant plate, and thickness is the ellipsoid shape less than 0.5mm, the filtering hole of gathering on it, and the filtering hole diameter is less than the minimum weep hole diameter on the orifice plate.The edge of bushing 2a is fixed on the flange 2b, and flange 2b external diameter equals the internal diameter of STEAM TRAP circular shell, and flange 2b also makes with corrosion resistant plate, and it is thicker slightly than bushing 2a, best some elasticity, it and shell inner surface drive fit.

From the part section of the represented orifice plate of the present invention of Fig. 3 as can be seen, also have sectional shape difference, other hole that function is different up and down at each weep hole, by hydrophobic flow direction, these holes are successively: tapped hole 4a, shrinkage hole 4b, weep hole 4, unthreaded hole 4c, they interconnect on same center line, form the through hole one by one on the orifice plate, in each through hole, the diameter d minimum of weep hole 4.The screw thread of tapped hole 4a and institute's wire distribution stifled 5 is coarse plain thread, and its nominal diameter is more than 2 times or 2 times of weep hole 4 diameter d in its place through hole, and 5 equal in length are blocked up in the length of tapped hole 4a and institute's wire distribution, and it is worth greater than 1/2 of tapped hole 4a nominal diameter.That link to each other with tapped hole 4a outlet is shrinkage hole 4b, shrinkage hole 4b is that circular cone shrinks shape, angle of throat is 60 °, shrinkage hole 4b inlet diameter is less than or equal to the path of coupled tapped hole 4a, the diameter of the weep hole 4 that shrinkage hole 4b outlet diameter equals to join with it, the length of shrinkage hole 4b is 0.5～1 with the ratio of weep hole 4 diameter d.What link to each other with shrinkage hole 4b outlet is weep hole 4, and weep hole 4 is uniform section circular holes, and the length of weep hole 4 is 0.5～1 with the ratio of its diameter d.That join with weep hole 4 outlet is unthreaded hole 4c, and unthreaded hole 4c also is the uniform section circular hole, and its diameter is equal to or greater than 1.6 with the ratio of its institute's weep hole that connects 4 diameter d, and the length of unthreaded hole 4c is equal to or greater than 1 with the ratio of weep hole 4 diameter d.The function in above-mentioned each hole is: tapped hole 4a and institute's wire distribution stifled 5 is to be used to enable or to block corresponding weep hole 4, shrinkage hole 4b is in order to reduce the flow resistance of weep hole 4 inlets, weep hole 4 is to be used to the hydrophobic area that provides certain, and unthreaded hole 4c is the end for the fixing drain pipe that links to each other with weep hole 4.The needs that how much depend on of number of openings are arranged the quantity of weep hole on the orifice plate, arrange 2～4 weep holes usually on orifice plate, therefore also just need 2～4 through holes, and dispersed placement is on orifice plate.

The represented drain pipe of the present invention of Fig. 4 is common smooth straight, its internal diameter equals the diameter d of the weep hole that connects, its external diameter equals to fix on the orifice plate diameter D of the unthreaded hole of its connecting end, the hydrophobic outlet port of drain pipe is expansion shape, the angle of flare is 16 °, expansion length equals 2 times of drain pipe inner diameter d, and the material of drain pipe is stainless steel or brass.

Claims

1. steam trap that is used for gas utilization unit discharged steam water of condensation, it comprises the housing (1) of STEAM TRAP, be separated into water space into perpendicular to hydrophobic flow direction and with housing (1) inner space and go out the water space orifice plate (3), place the into filter screen in water space (2), it is characterized in that:

Orifice plate (3) is gone up dispersed placement a plurality of through holes, is generally 2～4 through holes;

Each through hole is formed by connecting by 4 different holes on same center line, and along hydrophobic flow direction, they are successively: tapped hole (4a), shrinkage hole (4b), weep hole (4), unthreaded hole (4c), wherein the diameter d minimum of shrinkage hole (4);

Orifice plate (3) is gone up normally ascending the having nothing in common with each other of diameter d of each weep hole (4);

Each tapped hole (4a) all is furnished with the plug (5) of identical screw thread;

Along hydrophobic flow direction, each weep hole (4) connects a drain pipe (6), the connecting end of drain pipe (6) is fixed in the adjacent unthreaded hole (4c) of weep hole (4), the internal diameter of drain pipe (6) equal the diameter d of the weep hole that connects (4), the other end opening the going out in the water space of drain pipe (6) in STEAM TRAP housing (1).

2. according to the described steam trap of claim 1, it is characterized in that: filter screen (2) is made of bushing (2a) and flange (2b), bushing (2a) material is a corrosion resistant plate, thickness is less than 0.5mm, be the ellipsoid shape, densely covered filtering hole on it, the filtering hole diameter is gone up minimum weep hole diameter less than orifice plate (3), bushing (2a) edge is fixed on the flange (2b), flange (2b) is to use than the thick slightly corrosion resistant plate of bushing (2a) to make, flange (2b) external diameter equals the internal diameter of STEAM TRAP circular shell (1), it and housing (1) internal surface drive fit.

3. according to the described steam trap of claim 1, it is characterized in that: the screw thread of each tapped hole (4a) and institute's wire distribution stifled (5) is coarse plain thread, nominal diameter is more than 2 times or 2 times of weep hole (4) diameter d in its place through hole, the equal in length of tapped hole (4a) and institute's wire distribution stifled (5), it is worth greater than 1/2 of tapped hole (4a) nominal diameter.

4. according to the described steam trap of claim 1, it is characterized in that: each shrinkage hole (4b) is circular cone and shrinks shape, angle of throat is 60 °, shrinkage hole (4b) inlet diameter is less than or equal to the path of coupled tapped hole (4a), the outlet diameter of shrinkage hole (4b) equals the diameter d of coupled weep hole (4), and the ratio of the length of shrinkage hole (4b) and weep hole (4) diameter d is 0.5～1.

5. according to the described steam trap of claim 1, it is characterized in that: each weep hole (4) is the uniform section circular hole, and the length of weep hole (4) is 0.5～1 with the ratio of its diameter d.

6. according to the described steam trap of claim 1, it is characterized in that: each unthreaded hole (4c) is the uniform section circular hole, the ratio of unthreaded hole (4c) diameter D and its institute's weep hole that connects (4) diameter d is equal to or greater than 1.6, and the ratio of unthreaded hole (4c) length and its institute's weep hole that connects (4) diameter d is equal to or greater than 1.

7. according to the described steam trap of claim 1, it is characterized in that: each drain pipe (6) is common smooth straight, its external diameter equals the fixedly diameter of the unthreaded hole (4c) of drain pipe (6) connecting end, the optimum length of drain pipe (6) equals 15 times of its inner diameter d, drain pipe (6) outlet port endoporus is expansion shape, the angle of flare is 16 °, and expansion length is 2 times of drain pipe (6) inner diameter d, and the material of drain pipe (6) is stainless steel or brass.